Myasthenia Gravis Case StudyPosted on 5/01/07

By Kathleen Moreo, RN, Cm, BSN, BHSA, CCM, CDMS

Myasthenia gravis Case Study Myasthenia gravis is a chronic autoimmune neuromuscular disease characterized by varying degrees of muscle weakness that usually increases during periods of activity and improves after periods of rest. Although myasthenia gravis may affect any voluntary muscle, muscles that control eye and eyelid movement, facial expression, and swallowing are most frequently affected.

Part I-- A healthy male, age 61, presents to the ophthalmologist in September 2006 with a complaint of double vision. He is employed full-time in a physically demanding job and is in good physical condition. He denies use of any medications except 81 mg aspirin daily. The ophthalmologist refers the patient to a second ophthalmologist who specializes in affected eye muscles.

The patient is seen by the ophthalmology specialist in October 2006, who takes a medical history and physical and neurological examination. The specialist reports that he is restricted from ordering a full panel of labs by the patient’s health plan, and opts to test the patient’s thyroid in addition to routine diagnostic tests. Test results are normal.

In November 2006, the patient experiences eye-droop and returns to the specialist. A blood test is ordered to detect the presence of immune molecules or acetylcholine receptor antibodies. (Most patients with myasthenia gravis have abnormally elevated levels of these antibodies.) The blood test confirms a diagnosis of myasthenia gravis, and the patient is referred to a neurologist.

The patient sees the neurologist in November 2006, who treats the patient with pyridostigmine 60 mg three times a day and orders intravenous immunoglobulin (IGIV) as plasma protein replacement therapy. The health plan approves a 3-month course of IGIV. In December 2006, the patient receives a start-up 5-day course of IGIV therapy. The patient is given follow-up maintenance therapy with once-per-month treatments of IGIV in January 2007 and February 2007. The patient tolerates the therapy without incident.

March 14, 2007 - The patient notices his eye starting to droop. He contacts his neurologist, who contacts the health plan to request continued monthly maintenance with IGIV therapy. The ongoing treatment is denied by the health plan. The patient’s muscle weakness spreads to his hands and fingers, impacting his ability to work.

April 4, 2007 - He sees his neurologist, who prescribes IV treatment of methylprednisolone, 1000 mg continuous-drip, administered through home-health care. A home-health case manager contacts the patient to initiate home-health IV therapy. The patient tolerates the infusion without incident.

April 11, 2007 - The patient experiences trouble breathing. He contacts the neurologist to report distress with breathing and also describes his eye as “turned in”. He states he is concerned about the “steroid treatment” he is receiving The neurologist informs the patient that the medication may have an adverse effect of anxiety, but that it is important for the patient to remain on the treatment.

April 12, 2007 - The patient presents to the emergency room with labored breathing. The ER physician admits the patient with a diagnosis of suspected pneumonia. Cultures are taken and IV antibiotic (levofloxacin) is ordered. Platelet count is 181,000/mcL.

April 13, 2007 - The patient receives a CT scan of the chest which confirms pneumonia. At 11:00 pm in the evening, the patient’s breathing difficulty escalates. His blood pressure has climbed to 213/136 and blood sugar is 260. The attending admits the patient to the ICU on a Bilevel Positive Airway Pressure machine (BiPAP) for acute respiratory failure and myasthenia gravis crisis. [The use of BiPAP avoids intubation.] The patient is placed on BP medication and consults are ordered for cardiology, endocrinology, pulmonary and neurology.

April 14, 2007 - The patient's platelet count is at 130,000/mcL. The neurologist orders plasmapheresis to treat the myasthenia gravis crisis. A port is placed for the plasmapheresis treatment. [Myasthenia gravis can be successfully treated using plasmapheresis in addition to oral medications. Antibodies present in the MG patient's plasma cause an interference at the nerve-muscle junction; this communication-disconnect leads to muscle weakness. By removing plasma from the patient’s own blood and replacing it with a plasma substitute, then returning the blood supply to the patient’s body, some symptoms of muscle weakness can be eliminated.]

April 15, 2007 - The first plasma exchange is delivered to the patient in the ICU. The patient remains on ventilator support. Portable chest X-rays continue.

April 18, 2007 - The patient’s heart rate climbs dramatically to 176. The cardiologist intervenes and orders a STAT change of medication. The patient’s heart rate, BP and other vitals are monitored continuously until the patient is stabilized. Once stabilized, he is removed from the BiPAP.

April 20, 2007 - The patient's platelet count drops to 99,000/mcL. The patient is converted to oral antibiotics and stepped-down to a regular unit.

April 21, 2007 – Cardiology orders a stress test.

April 23, 2007 - Cardiology orders an angiogram due to an inconclusive stress test. Results are negative. All consults agree to a safe discharge. The patient is discharged on pyridostigmine 60 mg for control of the myasthenia gravis; levofloxacin 500 mg for pneumonia; diltiazem CD 180 mg for elevated BP; pantoprazole 40 mg for acid reflux; and albuterol INH to control SOB.

Post Script: The patient’s extensive hospitalization may have been avoided if the health plan had approved continuation of the maintenance IGIV therapy, particularly in light of the fact that the patient’s

symptoms were controlled with the maintenance therapy in January and February. Denial by the health plan may have been associated with IGIV’s off-label use in myasthenia gravis. IGIV is used off-label for other autoimmune diseases, as well. Treatment is usually an initial 5-day course, followed by once-per-month maintenance therapy if tolerated by the patient. IGIV contains IgG immunoglobulins (antibodies extracted from the plasma of over a thousand blood donors). It is a noticeable up-front expense, but it can save thousands of dollars in reduced hospitalization and treatment costs, as well as improve patient safety and quality of life, as this case study so aptly demonstrated.

http://primeinc.org/casestudies/casemanager/study/488/Myasthenia_Gravis_Case_Study